<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .contentBox {
            width: 200px;
            height: 200px;
            background-color: skyblue;
            display: flex;
            align-items: center;
            justify-content: center;
        }
    </style>
</head>

<body>
    <div id="app">
        <!-- 选项标题 -->
        <ol>
            <li v-for="(item,value) in title">
                <span @mouseenter="index=value">{{item.item}}</span>
            </li>
        </ol>
        <!-- 选项内容 -->
        <div>
            <template v-for="(item2,value2) in contents">
            
            <div class="contentBox" v-show="value2===index">                
                    <span>{{item2.item}}</span>
                </ul>
            </div>
        </template>
        </div>
    </div>

    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    <script>
        let vm = new Vue({
            el: "#app",

            data: {
                index:0,
                title: [{
                    item: 'html'
                },
                {
                    item: 'css'
                },
                {
                    item: 'js'
                },
                {
                    item: 'vuejs'
                },
                ],
                contents: [{
                    item: 'html-contents',

                },
                {
                    item: 'css-contents',

                },
                {
                    item: 'js-contents',

                },
                {
                    item: 'vuejs-contents',

                }
                ],
                get: [false, false, false, false]
            },
            methods: {
         

            }
        });
    </script>
</body>

</html>